1 files changed, 150 insertions, 0 deletions

diff --git a/lcmtype/eventlog.h b/lcmtype/eventlog.h
new file mode 100644
index 0000000..8999b1c
--- /dev/null
+++ b/lcmtype/eventlog.h
@@ -0,0 +1,150 @@
+#ifndef _LCM_EVENTLOG_H_
+#define _LCM_EVENTLOG_H_
+
+#include <stdint.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef LCM_API_FUNCTION
+#ifdef WIN32
+#define LCM_API_FUNCTION __declspec(dllexport)
+#else
+#define LCM_API_FUNCTION
+#endif // WIN32
+#endif // LCM_API_FUNCTION
+
+/**
+ * @defgroup LcmC_lcm_eventlog_t lcm_eventlog_t
+ * @ingroup LcmC
+ * @brief Read and write %LCM log files
+ *
+ * <tt> #include <lcm.h> </tt>
+ *
+ * Linking: <tt> `pkg-config --libs lcm` </tt>
+ *
+ * @{
+ */
+
+typedef struct _lcm_eventlog_t lcm_eventlog_t;
+struct _lcm_eventlog_t {
+    /**
+     * The underlying file handle.  Use this at your own risk.  Example use
+     * cases include implementing your own seek routine for read-mode logs, or
+     * rewinding the file pointer to the beginning of the log file.
+     */
+    FILE *f;
+    /**
+     * Do not use.
+     */
+    int64_t eventcount;
+};
+
+/**
+ * Represents a single event (message) in a log file.
+ */
+typedef struct _lcm_eventlog_event_t lcm_eventlog_event_t;
+struct _lcm_eventlog_event_t {
+    /**
+     * A monotonically increasing number assigned to the message to identify it
+     * in the log file.
+     */
+    int64_t eventnum;
+    /**
+     * Time that the message was received, in microseconds since the UNIX
+     * epoch
+     */
+    int64_t timestamp;
+    /**
+     * Length of @c channel, in bytes
+     */
+    int32_t channellen;
+    /**
+     * Length of @c data, in bytes
+     */
+    int32_t datalen;
+
+    /**
+     * Channel that the message was received on
+     */
+    char *channel;
+    /**
+     * Raw byte buffer containing the message payload.
+     */
+    void *data;
+};
+
+/**
+ * Open a log file for reading or writing.
+ *
+ * @param path Log file to open
+ * @param mode "r" (read mode) or "w" (write mode)
+ *
+ * @return a newly allocated lcm_eventlog_t, or NULL on failure.
+ */
+LCM_API_FUNCTION
+lcm_eventlog_t *lcm_eventlog_create(const char *path, const char *mode);
+
+/**
+ * Read the next event in the log file.  Valid in read mode only.  Free the
+ * returned structure with lcm_eventlog_free_event() after use.
+ *
+ * @param eventlog The log file object
+ *
+ * @return the next event in the log file, or NULL when the end of the file has
+ * been reached.
+ */
+LCM_API_FUNCTION
+lcm_eventlog_event_t *lcm_eventlog_read_next_event(lcm_eventlog_t *eventlog);
+
+/**
+ * Free a structure returned by lcm_eventlog_read_next_event().
+ *
+ * @param event A structure returned by lcm_eventlog_read_next_event()
+ */
+LCM_API_FUNCTION
+void lcm_eventlog_free_event(lcm_eventlog_event_t *event);
+
+/**
+ * Seek (approximately) to a particular timestamp.
+ *
+ * @param eventlog The log file object
+ * @param ts Timestamp of the target event in the log file.
+ *
+ * @return 0 on success, -1 on failure
+ */
+LCM_API_FUNCTION
+int lcm_eventlog_seek_to_timestamp(lcm_eventlog_t *eventlog, int64_t ts);
+
+/**
+ * Write an event into a log file.  Valid in write mode only.
+ *
+ * @param eventlog The log file object
+ * @param event The event to write to the file.  On return, the eventnum field
+ * will be filled in for you.
+ *
+ * @return 0 on success, -1 on failure.
+ */
+LCM_API_FUNCTION
+int lcm_eventlog_write_event(lcm_eventlog_t *eventlog,
+                             lcm_eventlog_event_t *event);
+
+/**
+ * Close a log file and release allocated resources.
+ *
+ * @param eventlog The log file object
+ */
+LCM_API_FUNCTION
+void lcm_eventlog_destroy(lcm_eventlog_t *eventlog);
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif